A user of a mobile phone sometimes uses the phone while not holding it. For example, the user may want to use a phone while driving a car. At this time, it is difficult for the user to interact with the phone because traditionally the user must touch the input device of the phone to provide instructions.
In addition, sometimes a user may want to use many applications of a handheld computer but it is inconvenient or impossible for the user to watch the display of the handheld computer. For example, the user may be blind. The user may want to listen to music, check for weather, receive and reply to emails and get the latest stock quotes, all without having to watch the handheld computer.